Certainly, it is possible for one to disagree with the ideological position and follow the practice of non-consumption alone. Some Muslims claim to follow a vegan lifestyle, claiming that they simply do not enjoy meat, for health, or even spiritual reasons, such as abstaining from the luxuries of life.

This position should not, however, carry over into what is called a “ragban” (an aversion, or turning away from the sunnah). Any Muslim who abstains from eating meat must be sure that there is no hatred, dislike, or indifference in their heart toward the practice, nor the one who performs it, as it is Islamically established. Any Muslim who claims to follow a vegan lifestyle in consumption must disagree with the contradictory aspects.

If a Muslim refuses to perform sacrifices upon the practice or “ethic” of the “veg lifestyle,” then they are willingly abstaining from mandatory religious practices. This is a major problem, as not performing mandatory religious obligations is sinful and punishable.

The impossibility to complete Hajj
Hajj is a mandatory act which must be performed at least one time in every adult Muslims lifetime. Part of the ritual of Hajj is the slaughtering of an animal. There are three types of Hajj, but the most common type and the one undertaken by almost every Haaji is known as Hajj Tamat`tu – where the Haaji wheres the Ihram and first performs Umrah, he then takes off the Ihram and when the days of Hajj arrive, he then puts on the Ihram for Hajj, now because Allah afforded him with the opportunity of performing Umrah and Hajj with two different Ihrams on one journey it becomes Wajib for him to slaughter an animal. Allah also makes mention of this command in the Holy Quran:
فَمَن تَمَتَّعَ بِٱلْعُمْرَةِ إِلَى ٱلْحَجِّ فَمَا ٱسْتَيْسَرَ مِنَ ٱلْهَدْىِ ۚ
If in peacetime anyone wants to take the advantage of performing Umrah and Hajj together, he should make an offering which he can afford, [Al Baqarah 2: 196]
Jabir bin ‘Abdullah RA, describing the Hajj of Allah’s Apostle (ﷺ) said:

عَنْ جَابِرِ بْنِ، عَبْدِ اللَّهِ قَالَ كُنَّا نَتَمَتَّعُ مَعَ رَسُولِ اللَّهِ صلى الله عليه وسلم بِالْعُمْرَةِ فَنَذْبَحُ الْبَقَرَةَ عَنْ سَبْعَةٍ نَشْتَرِكُ فِيهَا ‏.‏
We performed Hajj Tamattu’ along with Allah’s Messenger (ﷺ) and we slaughtered a cow on behalf of seven persons sharing in it. [Sahih Muslim 1318]

Hajj cannot be completed without this step, and nullifies the performance of the ritual.
So if you are not going to sacrifice and slaughter an animal during your Hajj, how is your Hajj possibly going to be done?

And if you believe that slaughtering animals is cruel, than are you saying that Allah has made it incumbent on us to perform an act that is actually cruel? You certainly will have to check your Imaan if you believe this!