[DISCUSSION] Should Sivir still be hit by the same spell twice even if she blocks it?

Now I apologize for the title, because I didn't know any other way to summarize the issue I'm trying to discuss.

1. As an example, Lulu's q has two parts to it. If she q's a Sivir, and Sivir blocks it, usually the second "part" of Lulu's q will still damage and slow Sivir.

2. Second example: If you are grouped with your team, and Sejuani ults your whole team, you can spellshield Sejuani's ultimate, but you will still be stunned and have your spellshield popped, because even though you blocked the initial hit, but it will still splash onto you from hitting your teammates.

3. Third example: Thresh's flay is technically two parts. In certain positions, Thresh can actually pop Sivir's spellshield with flay, and still have his flay go through.

Now, I might be biased because I am a Sivir player, but out of all these examples, doesn't it seem counterintuitive to the gameplay interaction Riot wanted to achieve with spellshield? When you block a spell, you should block the spell. You shouldn't still be hit by it due to some random gimmick. You shouldn't be hit by a spell TWICE. That's like double jeopardy. Thoughts?