With some niche plugins and other features you'd like to see in C4D I'd say "be careful what you wish for".
If MAXON were to add explosions/fluids/etc they'd probably be pretty good and have some nice features and integration...but likely not really be as advanced like the current 3rd party options. And then the third-party options would die off or never be created in the first place because the feature was already in C4D so far fewer people would potentially buy their product. And when MAXON does add some big new feature they seem to just leave it as it was first released for years or decades (BodyPaint), with only minor incremental changes. So, we'd soon have an out-of-date explosion/fluid system and no third-party options. This would hurt C4D in the long run...really bad.
As for cost of XP/etc...yes $600 (or whatever) is a big investment. But if you are a professional you need to invest in your business, and should be able to offset the costs of running your business with the work you can do because of the investment (that is how business works). I have a landscaper friend who laughs at how cheap our business is to run compared to what we can earn. He just needed to buy a new Bobcat - he bought a 10-year-old Bobcat for $14,000 that will take him years to pay off. You could easily pay off XP in a single job.
If you need explosions consider XP - their team works really hard to make a great product that adds major capabilities to C4D that allows alot of other people to earn more money.