"Imperial" is Twilight Imperium's biggest design flaw (IMO, of course). As you'll typically get the card about twice in a game, and 2 vps is a winning margin in almost all circumstances, it makes the mid/endgame entirely about being the first person to grab Imperial for a second time. In turn, this forces choice of card 1 to get the initiative whenever possible, so you can take "Imperial". Which eliminates a lot of the interest provided by the actual strategies.
Your opinion is widespread, and the official Twilight Imperium variants FAQ has an "Ancient Throne" variant designed to deal with this problem. Play with the "Age of Empire" variant in the rulebook (i.e. face-up Objective cards), and replace the primary ability of "Imperial" with:
Imperial Claim
Choose either a) or b).
a) If you control Mecatol Rex, immediately gain 1 victory point. Also, regardless of your control of Mecatol Rex, during the upcoming Status Phase, you may qualify for any
number of Public Objective Cards (but must still meet the individually stated requirements of each card).
b) You may choose to execute the secondary ability of the Imperial Strategy Card (at no cost). No other player may execute this secondary ability this game round.
Play the secondary as normal.
This became such a popular solution that they printed an "Imperial II" card with this wording in the "Shattered Empire" expansion.
The expansion also contains a more complex solution: It has a variant completely-different set of strategy cards for an alternate style of play; obviously this avoids the problem entirely.