When was the last time you heard of Warcraft IV? I rest my case.

to be fair, zenimax is doing it, not bethesda, so in that case, im not worried, elder scrolls 6 will come

This issue has been brought up in several threads in the Elder Scrolls Online forum, you're welcome to jump into one of those discussions.

As Robmomanjaro has already pointed out TESO is being developed by a different studio so BGS is available to make more single player RPGs.