I thought it had more to do with the high cost of the series? They weren't filming these on the backlot at Universal!
Some episodes were pretty good, (Indy caught up in WW1 spy intrigue) others were about as dry as an old history textbook. IIRC, one whole episode was Indy wrestling with the decision to enlist and nothing else. Not exactly an action packed episode. I couldn't make it through any of the kid Indy episodes.
The show did continue on cable tv as a series of tv movies though.
Funny how really old Indy has ended up on the cutting room floor next to Sebastian Shaw's Anakin.
I thought the episode where Harrison came back to do the wraparound story was good. Kind of like that final episode of Galactica 1980 with Starbuck, it came too late.