Because as it is for the competition already TODAY isn't all about bc ....surely is a nice add on ...and Sony also if late is better to catch up on that.. with the ps5 ....The difference is we are potentially getting full Playstation 1/2/3/4 BC from the start of next gen, not years down the line when it's far too late. Being able to carry over your PS4 library is huge, why would you not want to invest in the PS5 knowing that.
But I'll take initially the console that will play most games better (very likely the most powerful then) and down the line the other for their exclusives