I can understand the want for more stealth based modes, but MGSV does lend it's self more to action so it shouldn't be that surprising that MGO is more action than stealth right now, both seem to look perfectly viable though.
Personally it really bums me out PC players have to wait so long as it looks so much better than MGS4's MGO.
MGS3's looked fun, but I completely missed out on that era, 4's was a nightmare, this actually already looks infinitely more practical in nearly every capacity. I'd like to hope we'll be getting updates and changes for a good few months to a year, which by then it'll probably be pretty damn incredible to play.
Though really, they should just treat this as a "platform" and expand on it endlessly, the MGSV gameplay is so rock solid that you could keep people invested in MGO for years and years as long as you keep building it up and adding to it, tweaking it here and there and so on. I think my biggest gripe with the game with everything I've seen is the Walkers really stand out as being kind "flow" ruining.