Criticism concerning tu-160 shouldn't be really directed against the plane itself but possibly against non stealthy bombers in general.
What usual roles can a bomber have?
A. cruise missile truck.
a1. Against an enemy nearby (mix of tactical and strategic targets possible)
a2. against an enemy a few thousand km away (probably strategic targets only)
a3. against an enemy across an ocean (10.000 km and more away, strategic targets only)
B. non-stand off strikes with cheaper weapons.
b1 against an enemy nearby, striking targets close to the border (probably tactical strikes)
b2 against a neary enemy, striking targets a few hundred km into enemy's territory (mix of tactical and strategic targets)
b3 against a nearby enemy, striking targets a few thousand km deep into enemy territory. (strategic targets)
b4 against an enemy far away (a few thousand km and more?)
Analysis: is there a way to do the same mission with a cheaper and less vulnerable platform?
a1 - most definitely. land launched cruise missiles, tactical fighter launched cruise missiles, even ships/subs IF otherwise already required by scenario.
a2 - probably. Tactical fighters with JASSM class cruise missiles could pull it off up to targets some 2000 km away from base, perhaps doubling that with IFR. IFR making economic sense only if required to be/exist there for other needs as well. Large land based cruise missiles, like Chinese cj10 model, could also cover this segment. Ships/subs could do it, but again, it'd be economic only if their existance otherwise already required for other roles as well.
a3 - air and land launched tactical options non existant. Bombers only option. Ship launched option possible, but perhaps too expensive to secure, to get actual fleet close enough over an ocean, depending on enemy's strength. Still, submarine launched option is a definite alternative to bomber launches. While even SSK could theoretically be used, due to their speed and endurance it's a bad option. Nation with SSNs, however, could very well depend on their sub launched cruise missiles. Downside would be more time required to deploy forces close enough to launch, meaning the fleet would be tied up for the mission. Overall, a decent alternative if one already has to have SSNs close by, but otherwise could be more expensive.
b1 - bad option. less survivable than tactical fighter delivery, even if cheaper per bomb dropped. Loitering not advisable anyway, due to enemy forces. Continuously being over one area is a death wish. Of course, all this assumes a capable enemy and no air superiority. If there is complete air superiority then the whole issue is moot as one could argue anything could drop bombs, even drones. Altnernatives such as land based strikes also possible and proliferating more and more each year with various gps/tv guided munitions. Due to little to no penetration into enemy lands, there'd be little warning to the enemy, so aircraft strikes could be performed with little support aircraft.
b2 - land based strikes not an option, but tactical fighter delivery still prefferred for same reasons. But due to actual penetration over contested skies and over lands littered with radars and SAMs, ample support aircraft would be needed. Those would also limit the range of overall strike package. Even if bombers could reach further, short legs of the support package and fighter escort would render such a mission suicidal.
b3 - this is really a continuation of above scenario, going farther. But, like it was mentioned above, without escorting assets such mission is really not smart. While unburdoned by support package the bomber could theoretically go very high altitude mach 2 all the way, it really isn't nearly enough to provide safety over literally a thousand or more km there and back. Plus the bomber may not have the fuel to actually go at mach 2 over 3-4 or more thousand km.
b4 - if the enemy is far away, but there is not necesarrily a need to go deep into its protected airspace, then long range bomber is virtually the only way to perform this mission. Though, I can't really think of many reasons why one'd want to strike at far away enemy with cheap, tactical weapons. Cruise missiles are a safer bet there.
Low level flight is an option but if we're talking about a equipped enemy which has its airspace well covered with radars, it's applicable only for little to no penetration into enemy space. The further one goes into enemy airspace, chances of detection increase, even if initially one creates a temporary initial ingress point free of enemy radars.
Also, all this applies to low RCS bombers as well. A b2 would also have a hard time performing a deep penetration mission on its own against a modern equipped enemy. while low rcs is better protection than speed, it only goes so far. for best results one would still need support packages, just like the US had over Serbia in 1999.
In my opinion, all this really means is that bombers are better left off as stand off weapon carriers in a high intensity war against modern enemy. it makes little sense using them for tactical weapon drops against tactical targets. Today they are used for such roles but against much weaker enemies and because bombers are already there and paid for. Countries that don't have the need for strategic strikes are not developing bombers. Only ones that do have them already are trying to find additional tactical strike roles for them so they can utilize them more and make the mission cheaper.
So, tu160 does have its merits, but the unfortunate thing is its low numbers, probably making its usage/maintennance pretty expensive due to fixed overhead costs. Magically changing every 2 or even 3 tu22m for 1 tu160 would be a much better deal for russia, in my opinion. But the medium-term future is going to be subsonic and stealthy, as both pak-da and new US bomber programme show.