Regarding these attacks being insignificant , I am not sure . Over the past few years , there must have been hundreds of attacks with much casualties and damage .
In the context of the war it is not turning the tide in favour of the ISIS terrorists Israel is supporting in this conflict...
But part of learning from experience is working out how to minimise casualties on your side too... which they are hopefully taking into account.
And the need to use many air defence assets . Who pays for them ? I am not sure if Syria pays or Russia or Iran donate some systems . So it costs money , whoever pays .
It is the best possible test of the system without the threat of US invasion and regime change.
Russia would be getting an excellent overview of what is happening and the Syrians are part of that air defence network now too and you would think over time the Israelis would be getting better with more success, but it seems that the Syrians are getting better too.
The Americans may be able to afford this
In money terms this is probably all free to Israel, and the US will be seeing this as real world tests too so they will be interested in the results as well, but no matter what they say publicly, internally it might be rather interesting listening to US MIC people explain the failures of their systems over and over and their attempts to tweak them to get them to be more effective and more efficient and having them get shot down again and again.
I am pretty sure the makers of the F-35 would like to say that the F-35 can dominate Syrian airspace at will and drop cheap dumb bombs to take out targets because all the Russian air defence stuff is useless against it, but instead the Israelis are using F-16s for these attacks... and why wouldn't they... they are not stealthy either but orders of magnitude cheaper to operate and faster and better payload and better range....
Especially if it costs less to attack and more to defend . But can Syria afford it ?
The point is that no one can afford not to defend, but creating an organised integrated air defence network is the key to any defence...
Without an IADS you basically have individual groups that might work localised as small teams but are not coordinated and working together.
Very simply having a central radar network that offers excellent large area coverage means your individual batteries don't need to remain on high alert 24/7 giving away their own positions using their own radars all the time so they can see what is coming.
Imagine the performance of a fire brigade if they had to drive around the place all the time looking for smoke... imagine a fire occurring at the end of a 10 hour shift for instance... whereas instead having your fire fighters at the station cleaning and doing maintenance but waiting for a call means they are more ready to respond and deal with fires.
Even if they could , why should they waste money ? When a simple Rocket or drone does a better job ? Let the attackers defend and run out of expensive SAM . Use a drone or Rocket instead to hit them . Syrians can borrow some from Lebanon or Yemen . Problem solved .
Syria attacking Israel the way Israel attacks Syria would lead to serious escalations in attacks and a lot of sympathy for Israel, and it would actually do much good either... Israel would escalate attacks rather than stop them... and an escalation does not help Syria...