Should they though? At one point they were dominant because they pulled in crowds like no other team (they still do) and were able to sustain much larger budgets than other teams largely from gate receipts.
Through a combination of the salary cap, increasing central funding from television deals and the RFU, rich people bankrolling other teams etc., the Tigers' impressive attendance figures no longer count for as much. Tigers can't automatically outspend teams anymore, so I think the expectation from Tigers' fans should be rebalanced. Gloucester are paying as much, if not more, on their squad, yet routinely finish below Tigers. I'm not really seeing why Tigers should have higher expectations to be honest.